Hartley Magazine

All the latest news, hints, tips and advice from our experts


The pelargoniums and aeoniums still sheltering in the mini greenhouse need to make way now for tender vegetable seedlings.

This is a dicey moment in the year for greenhouse plants. Ideally, I would leave my slightly tender ones that have been overwintering in my miniature greenhouse in there a little longer. The temperature is still low, particularly at night, and there is a good chance of a frost still. But this is boom time in the greenhouse, its most packed month of the year, and the next generation is nudging the overwinter stalwarts out of the way. I need to make room for the young tomato, aubergine, melon and chilli plants that have been cluttering up my windowsills and that will spend the rest of the summer in the greenhouse. But I also need to space for the plants that will be going outside next month, the courgettes, lettuces, French and runner beans and peas that would struggle to germinate while the soil temperature is still low, but will benefit from the head start.

Temperatures can still drop very low, this month and next, and it is worth remembering that many European countries have traditions around the so-called ‘Ice Saints’, St Mamertus, St Pancras and St Servatius, whose feast days fall on the 11th, 12th and 13th of May respectively and are said to often bring the final frosts of spring (sometimes they are joined by Saint Sophia’s Day on the 15th, or ‘cold Sophia’). So watch out, it isn’t necessarily over yet. All of which makes me a little trepidatious about what I must now do, which is to cast my delicate overwinterers out into the cold. Chief in importance here are my aeoniums, which have grown to a decent size over the years and which I would be very annoyed to lose to a late frost. But I also have a good selection of pelargoniums that I like to keep going from year to year, including some scented ones. We have been lucky this past winter. In some years it gets so cold that I have to put a heat mat in at the bottom of the greenhouse, just to provide a tiny bit of heat to keep the frosts off. The greenhouse being miniature, I have also swathed the whole thing in blankets and old rugs at these times, to seal the heat in further. None of this has been necessary this winter, and we have had just a smattering of snow and only a few light frosts. Everything has come through well.

But yes, of course I am aware that all of this luck could be undone by an ice saint, or well before that. Therefore it’s important now, just as it is when acclimatising plants later from greenhouse to veg beds, to take some precautions and to ease the plants in gently. The plants I am taking out now will only be going as far as the terrace outside my back door, and so for now they can be moved into a very sheltered spot, tucked into our sunniest corner right under the kitchen window. I am throwing some fleece over them at night too, and that can stay during the day if there are any particularly cold snaps. Once they are through the first couple of weeks and if the weather is looking good, they can start to have a little post-winter TLC, potting them on into slightly larger pots, if they are small enough, or if they are too big for this then just scraping off the top layer of compost and replacing it, before starting them on their summer regime of regular watering and feeding. All of this will have to wait though. We have a tentative, in-between times on our hands right now, but those summery days are on their way.